Well known in the state of the art are built-in shower trays (tiled), the construction of which is a common practice in the USA, which involves the need to prepare the drain area on the floor, a sloped base that leads to said drain and waterproofing protection for the entire surface.
In using ceramic coatings or natural stone in moist areas such as showers, it is common for a waterproofing membrane to be installed in order to contain and drain the water, as well as to provide proper protection for construction materials against the effects of the moisture.
In line with the standards and regulations which regulate these types of installations, the waterproofing membrane must slope towards the drain and connect to it, forming a watertight seal. Therefore, properly making the connection between the waterproofing protection and the drain is a determining factor in correctly building a built-in shower that complies with the aforementioned regulatory criteria.
In the traditional way of constructing shower bases, this connection is not very difficult, given that due to the materials used, the membrane and the base for fixing the clamping ring, which comes fixed to the waterproofing on the drain body, can easily be placed so as to remain flush.
Commonly used in a conventional installation is a non-adhesive membrane, on which a thick mortar bed is used as a base to which the ceramic coating or natural stone is adhered, and which is not protected by waterproofing.
Non-adhesive membranes are directly arranged on the floor, or on a thin layer of sloped mortar. The drain must always be connected at the same level as the clamping ring, which is usually at floor level, and in the case that it is above the floor, said point is adjusted simply by varying the thickness of said sloped mortar, thereby achieving the desired leveling of the surface.
By using different construction materials and techniques, significant improvements have been made in the quality and finishes of these types of installations, such as a waterproofing with greater protection applied directly below the tiling by means of adhered membranes, placing the tiles in thin layers, using a substrate of panels to reinforce the installations with less thickness and weight, among other techniques.
However, with these new construction materials and techniques which are combined with traditional construction methods, there is often an unevenness of the elements that interact in said construction, which complicates the connection between the waterproofing membrane and the drain of the installation.
Therefore, with the aim of providing a more complete protection membrane and of not leaving the mortar bed base for tile placement exposed to moisture with each use of the shower, it is necessary to use an adherent-type membrane (according to the provisions in the ANSI A118.10 Standard).
Considering the requirements and restrictions established by the different regulatory codes and standards, the installer will find the following circumstances:
With respect to the floor drain, it must be in accordance with the plumbing codes (and/or in accordance with the ASME A112.18.2 Standard) and must have a clamping ring for connection to the waterproofing, with the aim of mechanically fixing said waterproofing, or it must have a flange integrated as the base for the adherence thereof.
In the case of drains with clamping rings, the drain body is connected to the drain pipe generally below the floor level and is supported and fixed to the surface of the support floor, such that the clamping ring is at the same level.
With regard to the sloped base made of mortar, to ensure a correct drainage of the shower water, the current regulations and codes demand a minimum 2% (¼″ per foot [0.63 cm per 30 cm]) slope towards the mouth of the drain in the floor.
The minimum necessary thickness for this layer at its lowest point, joined to the drain, can create a vertical distance from the surface thereof, the level where the adhered membrane is placed, with respect to a hard floor, the level of the clamping ring flange. This height may vary from being practically flush in the case of concrete floors, to being over 3 cm (1¼″) in the case of wooden floors, depending on the possible substrates.
Typically, built-in shower drains incorporate systems to adapt to the height of the grate and which can remain flush with the surface of the pavement, but they do not contemplate systems for correcting level differences for connection with waterproofing.
On the market it is common to use drains with incorporated clamping rings in built-in showers, since they are the most extensive and well known in the sector. Also, they are usually the type of drains which are generally found installed in practically all cases in which an installation is being renovated or reformed, which is why the base can still be used and, therefore, it is not necessary to replace it, saving on costs and labor.
Found in the state of the art are shower drains with an integrated flange, to which an adherent-type membrane may be attached, but these are exclusive solutions for models from specific manufacturers, as well as for specific types of grates and finishes. In this case, when it is necessary to renovate or reform an installation, it is usually obligatory to completely substitute the existing drain, which comes with the costs of the replacement parts and labor.
Additionally, also found on the market are pre-manufactured pieces of impermeable sheets which are have different fixed heights, and in which it is necessary to first make the sloped base, then measure the difference in level with the coupling flange of the clamping ring, and at that point check the version that best adjusts to the necessary measurement, which requires a previous study of the construction that is to be carried out, and necessarily results in a delay in achieving the same.
In light of all the foregoing, an element or procedure for the installation which makes the placement of waterproofing on an adhered layer possible, facilitating the connection of the clamping ring, regardless of the level difference due to the thickness of the layers of the installation, and which is also suitable to be used with the majority of built-in shower drain models and trademarks currently found on the market has not been found in the state of the art.